This invention relates to a water resistant yet breathable multi-layer film and fabric containing laminate or construction, including multiple hydrophilic layers, that is durable and able to withstand a wide range of use conditions. These laminates are designed for constructing activewear garments such as running and cycling.
In recent years, hydrophilic films have come to represent performance in the water-resistant xe2x80x9cbreathablesxe2x80x9d market. However, the use of hydrophobic adhesives, necessary to gain wash durability, has limited the performance of standard hydrophilic laminates in terms of breathability. The disclosed multi-ply hydrophilic technology, incorporating a shielded hydrophilic adhesive, provides a means to increase the water vapor transmission performance ceiling and create an array of new products. Significantly enhanced performance levels will allow lower cost inventive laminates to compete with existing higher cost materials.
In prior procedures, laminations to fabric of both hydrophilic and hydrophobic microporous films have typically relied on hydrophobic adhesives to attain the durability to laundering needed in breathable fabrics. Single film laminates frequently develop pinholes reducing the integrity and performance of the microporous film. Hydrophilic adhesives lacked suitable durability when exposed to wash conditions primarily because they would inherently swell when exposed to water and the fact that they were typically attached to substrates with limited stretch. Typical arrangements also limited constructions to single film laminates because it was thought the use of additional film layers would reduce the overall breathability of the product. The use of hydrophobic adhesives to join multiple layers of films indeed reduced the overall breathability of the finished laminate even if both films were hydrophilic.
The use of non-breathable adhesives in conjunction with hydrophilic films is described in U.S. Pat. Nos. 5,660,918 and 4,761,324. It has now been determined that the use of hydrophilic adhesives in the laminate to join an additional layer of hydrophilic film resulting in a pair of hydrophilic films separated/adhered to each other by a hydrophilic adhesive can result in an increase in overall breathability of the laminate and this is the basis for the present invention.